Extendable leg rest for aircraft passenger seat

ABSTRACT

An aircraft passenger seat including a seat bottom, a seatback pivotably attached to the seat bottom, and an extendable and angularly deployable leg rest pivotably attached to the seat bottom, the leg rest including leg rest rails pivotably attached to the seat bottom, a translating cushion assembly carried on the leg rest rails, a rack and pinion mechanism arranged to drive cushion assembly translation along the leg rest rails, and a timing link pivotably attached to the seat bottom arranged to actuate the rack and pinion mechanism in response to angular movement of the leg rest.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority from U.S. Application No. 61/974,595filed Apr. 3, 2014, the entirety of which is incorporated by referenceherein.

TECHNICAL FIELD AND BACKGROUND OF THE INVENTION

The present invention relates generally to an extendable leg rest foruse with an aircraft passenger seat, and more particularly, to amechanism configured to extend the length of a deployable leg rest via arack and pinion driven by the angular deployment of the leg rest.

Premium and business class aircraft passenger seats commonly includereclining seatbacks and deployable leg rests for achieving comfortablereclined sitting and horizontal sleeping positions. In fixed-shellaircraft seats in which the seatback reclines to a degree relative to afixed-shell positioned behind the seatback, the leg rest typicallydeploys from a vertical position against the front of the seat to anelevated position at an angle to the floor. In lie-flat capable seats,the leg rest typically angularly deploys all the way to horizontal toform part of the bed.

In either seat type, it is not only desirable for the leg rest to adjustangularly, but also to extend lengthwise to accommodate passengers withlong legs. While some leg rests move apart from the seat bottom as theleg rest deploys angularly, others are configured to extend and retractindependent of the angular deployment of the leg rest. In eitherconfiguration, leg rest extension is typically accomplished using apantograph mechanism. Pantograph mechanisms are undesirable because oftheir bulkiness, complexity, and weight, and must also be carefullydesigned to avoid pinch points. Pantograph mechanisms are also noteasily reconfigurable to provide different extension ratios.

Therefore, what is needed is a compact leg rest extension design thatavoids scissor linkages, is easily reconfigured to achieve differentextension ratios, and improves the comfort and usability of the legrest.

BRIEF SUMMARY OF THE INVENTION

It is therefore an object of the invention to provide a leg rest thatextends in length as the leg rest deploys angularly.

It is another object of the invention to provide a leg rest that movesapart from the seat bottom as the leg rest pivots in the direction ofhorizontal.

It is a further object of the invention to provide a leg rest having alocking gas spring arranged to compress upon the force of leg reststowing and extend to assist leg rest deployment.

It is a further object of the invention to provide leg rest particularlysuited for fixed-shell aircraft passenger seats wherein the leg restdeploys to an angle to the floor short of horizontal.

It is a further object of the invention to provide a leg rest configuredto move with the seat bottom from an upright to a reclined sittingpositions, and including timing linkage arranged to move a cushionportion of the leg rest apart from the seat bottom as the leg restdeploys angularly.

It is a further object of the invention to provide a deployable andextendable leg rest assembly easily adapted to achieve differentextension ratios.

To achieve the foregoing and other objects and advantages, in oneembodiment the present invention provides an aircraft passenger seatincluding a seat bottom, a seatback pivotably attached to the seatbottom, and an extendable and angularly deployable leg rest pivotablyattached to the seat bottom. The leg rest includes leg rest railspivotably attached to the seat bottom, a translating cushion assemblycarried on the leg rest rails, a rack and pinion mechanism arranged todrive cushion assembly translation along the leg rest rails, and atiming link pivotably attached to the seat bottom arranged to actuatethe rack and pinion mechanism in response to angular movement of the legrest.

In another aspect, the angular deployment of the leg rest causes thetiming link to actuate the rack and pinion mechanism to drive thecushion assembly away from the seat bottom to extend a length of the legrest.

In another aspect, wherein the rack and pinion mechanism may include anoutboard toothed rack fixed to the cushion assembly, an inboard toothedrack slidable along one of the leg rest rails and pivotably attached toone end of the timing link, and a pinion gear arranged between theoutboard and inboard toothed racks such that rotation of the pinion gearmoves the outboard and inboard toothed racks in opposite directions.

In another aspect, the timing link may be pivotably attached at one endto a horizontally oriented post positioned on one side of the inboardtoothed rack.

In another aspect, the leg rest may include a locking gas springarranged between the seat bottom and leg rest such that stowing the legrest compresses the locking gas spring and deploying the leg restlengthens the locking gas spring.

In another aspect, a pivot attachment point of the leg rest rails to theseat bottom may be spaced from a pivot attachment point of the timinglink to the seat bottom.

In another aspect, the cushion assembly may include a cushion carried ontop of spaced frame members and front and rear transverse beam tubes.

In another aspect, the aircraft passenger seat may be a fixed-shell seatincluding a fixed shell positioned behind the seatback, and the leg restdeploys angularly toward horizontal.

According to another embodiment, the present invention provides afixed-shell aircraft passenger seat including an extendable andangularly deployable leg rest. The seat includes a seat bottom, aseatback pivotably attached to the seat bottom, a fixed-shell positionedbehind the seatback, and a leg rest pivotably attached to the seatbottom. The leg rest includes leg rest rails pivotably attached to theseat bottom, a translating cushion assembly carried on the leg restrails, a translation mechanism arranged to drive cushion assemblytranslation along the leg rest rails, and a timing link pivotablyattached to the seat bottom arranged to actuate the translationmechanism in response to angular leg rest movement.

In another aspect, angular deployment of the leg rest causes the timinglink to actuate the translation mechanism to drive the cushion assemblyaway from the seat bottom to extend a length of the leg rest.

In another aspect, the translation mechanism may be a rack and pinionmechanism including an outboard toothed rack fixed to the cushionassembly, an inboard toothed rack slidable along one of the leg restrails and pivotably attached to one end of the timing link, and a piniongear arranged between the outboard and inboard toothed racks such thatrotation of the pinion gear moves the outboard and inboard toothed racksin opposite directions.

In another aspect, the leg rest may deploy angularly to an angle shortof horizontal.

Embodiments of the invention can include one or more or any combinationof the above features and configurations.

Additional features, aspects and advantages of the invention will be setforth in the detailed description which follows, and in part will bereadily apparent to those skilled in the art from that description orrecognized by practicing the invention as described herein. It is to beunderstood that both the foregoing general description and the followingdetailed description present various embodiments of the invention, andare intended to provide an overview or framework for understanding thenature and character of the invention as it is claimed. The accompanyingdrawings are included to provide a further understanding of theinvention, and are incorporated in and constitute a part of thisspecification.

BRIEF DESCRIPTION OF THE DRAWINGS

Features, aspects and advantages of the present invention are betterunderstood when the following detailed description of the invention isread with reference to the accompanying drawings, in which:

FIG. 1 is a side elevation view of a fixed-shell passenger seatincluding an extendable leg rest according to an embodiment of theinvention;

FIG. 2 shows the seat of FIG. 1 with the leg rest in mid-position;

FIG. 3 shows the seat of FIG. 1 with the leg rest fully deployed andextended;

FIG. 4 is a detailed view of the underside of the seat shown in FIG. 1;

FIG. 5 is a detailed view of the underside of the seat shown in FIG. 2;

FIG. 6 is a detailed view of the underside of the seat shown in FIG. 3;

FIG. 7 is a perspective view of the underside of the leg rest showingthe rack and pinion mechanism; and

FIG. 8 is a perspective view of a second embodiment of a leg restextension mechanism including a belt and pulley arrangement.

DETAILED DESCRIPTION OF THE INVENTION

The present invention will now be described more fully hereinafter withreference to the accompanying drawings in which exemplary embodiments ofthe invention are shown. However, the invention may be embodied in manydifferent forms and should not be construed as limited to therepresentative embodiments set forth herein. The exemplary embodimentsare provided so that this disclosure will be both thorough and complete,and will fully convey the scope of the invention and enable one ofordinary skill in the art to make, use and practice the invention. Likereference numbers refer to like elements throughout the variousdrawings.

Referring to FIGS. 1-7, a first embodiment of an extendable leg rest isshown generally at reference numeral 20. Leg rest 20 is shown pivotablyattached proximate the forward end of a seat bottom 22 of an aircraftpassenger seat 24. Seat 24 as shown is a fixed-shell aircraft seatincluding a seatback 26 configured to recline within and relative to afixed-shell 27 positioned behind the seatback 26. Seat bottom 22 may bemoved to drive seatback movement between an upright sitting position fortaxi, take-off and landing (TTOL) as shown in FIG. 1, and a fullyreclined sitting position as shown in FIG. 3. The seat bottom 22 maytranslate forward and lower to the floor as the seat 24 adjusts fromupright to reclined, thereby carrying the pivotably attached leg rest 20along therewith.

The leg rest 20 is pivotably attached at one end to the seat bottom 22such that the leg rest is configured to pivot between a first positionstowed generally vertically against the front of the seat 24, and asecond position at an angle to the floor, for example, about 30-45degrees as shown in FIG. 3. The leg rest deploys angularly andpreferably steplessly between its stowed and fully deployed positionssuch that the leg rest can be positioned at any desired angle along itsrange of motion. The leg rest 20 may deploy independent of seat reclineor together with the seat recline movement. When employed on afixed-shell aircraft passenger seat as shown, leg rest deployment maystop short of achieving horizontal as a result of the limited seatbackrecline and lack of living space dedicated for this particular seat.When employed on a lie-flat seat capable such as a seat found in anindividual passenger suite, the leg rest preferably deploys tohorizontal to help form part of the bed. The leg rest 20 can be attachedto a variety of seat types that may or may not be configured to reclineand may or may not include a movable seat bottom.

In either seat configuration, the leg rest 20 is configured to extend inlength as it angularly deploys. In other words, the cushioned portion ofthe leg rest 20 moves farther apart from the seat bottom 22 the more theleg rest moves angularly toward horizontal. This lengthwise extensionenhances comfort and usability of the leg rest, particularly for longerlegged passengers.

The leg rest 20 is an assembly generally including parallel leg restrails 28, or “rails”, that move (i.e., pivot) together with each railpivotably attached at one end to the seat bottom 22, a cushion assembly30 slidably carried on the leg rest rails 28, and a rack and pinionmechanism 32 arranged to drive the translation of the cushion assembly30 along the length of the leg rest rails 28 as the leg rest 20 deploysangularly. The leg rest may further include a locking gas spring 34arranged to angularly deploy the rails 28.

The rack and pinion mechanism 32 includes parallel arranged inboard andoutboard toothed sliding racks 36, 38 meshed on diametrically opposingsides of a pinion gear 40 to drive the cushion 30 along the rails 28 asthe leg rest deploys angularly. As best shown in FIGS. 4-6, spacedtiming links 42 pivotably attached to the seat bottom 22 pivot about apivot axis spaced from a pivot axis of the leg rest rails 28. As the legrest 20 deploys angularly, the timing links 42 pull on the inboard setof sliding racks 36 to rotate the pinion gears 40 in one direction,thereby driving the outboard sliding racks 38 in the opposite directionof the pulling to move the cushion 30 apart from the seat bottom 22. Inother words, the timing links 42 pull the inboard rails 36 toward theseat bottom 22 as the leg rest deploys angularly, thereby rotating thepinion gears 40 to drive the outboard sliding racks 38 in the oppositedirection to drive the cushion 30 away from the seat bottom 22.

The outboard sliding racks 38 are fixed to the inboard sides of framemembers 44 on the underside of the cushion 30 such that movement of theoutboard sliding racks 38 moves the cushion 30. The cushion framefurther includes spaced front and rear transverse beams 46, 48 arrangedto keep the cushion square. The inboard sliding racks 36, one on eachrail 28, slide along the length of their respective rail 28. The timinglinks 42 pivotably attach to a post 50 carried on the inboard side ofeach inboard sliding rack 36. The teeth on the inboard sliding racks 36face the teeth on the outboard sliding racks 38 and the two sets ofracks are maintained parallel and they slide in opposite directions.

As the leg rest 20 deploys angularly, the timing links 42 pull on theinboard sliding racks 36 to rotate the pinion gears 40 in one direction(i.e., clockwise) to drive leg rest extension (i.e., cushion movement inthe direction away from the seat bottom 22). As the leg rest 20 stowsangularly, the timing links 42 push on the inboard sliding racks 36 torotate the pinion gears 40 in the opposite direction (i.e.,counterclockwise) to retract the leg rest (i.e., cushion movement in thedirection toward the seat bottom 22). Leg rest movement can beconsidered telescopic in that the cushion overlaps and translatesrelative to the underlying support structure.

The teeth on the respective racks 36, 38 and pinion gears 40 can bechanged to customize the extension ratio of the cushion to provide forgreater or lesser extension in certain applications. The extension ratiocan also be adjusted by changing the length on the timing links 42and/or position of their respective pivot axis relative to the pivotaxis of the rails 28.

As best shown in FIGS. 4-6, the locking gas spring 34 is arrangedbetween the seat bottom 22 and the rails 28 to drive the angulardeployment of the leg rest 20. Specifically, the locking gas spring 34is attached to the seat bottom 22 and a transverse member 35interconnecting the ends of the leg rest rails 28. When the leg rest 20is stowed as shown in FIG. 4, the locking gas spring 34 is compressedand “charged” (i.e., the piston is compressed into the cylinder). Whenthe leg rest 20 is deployed as shown in FIG. 6, the gas spring 34 isextended. The leg rest 20 can be stowed by pushing down on the leg restin the direction of the stowed position to charge the gas spring 34, andreleased by actuating a release switch.

Rack and pinion mechanisms may be provided on one side of the leg rest20, or on both sides to maintain parallelness. In an alternativeembodiment, the pinion gears 40 may be replaced with a pair of joinedpinions of differing ratios to achieve greater extension ratios.

Referring to FIG. 8, a second embodiment of an extendable leg rest isshown generally at reference numeral 60. This second embodiment employsa belt and pulley arrangement in place of the rack and pinion mechanismof the first embodiment. Specifically, timing linkage 62 may be used todrive a toothed cog belt 64 arranged on vertically oriented pulleys 66rotatably carried on pivoting leg rest rails 68. As the rails 68 deployangularly, the timing linkage 62 drives belt rotation, thereby drivingcushion movement.

The foregoing description provides embodiments of the invention by wayof example only. It is envisioned that other embodiments may performsimilar functions and/or achieve similar results. Any and all suchequivalent embodiments and examples are within the scope of the presentinvention and are intended to be covered by the appended claims.

What is claimed is:
 1. An aircraft passenger seat, comprising: a seatbottom; a seatback pivotably attached to the seat bottom; and anextendable and angularly deployable leg rest pivotably attached to theseat bottom, the leg rest comprising: (i) leg rest rails pivotablyattached to the seat bottom; (ii) a translating cushion assembly carriedon the leg rest rails; (iii) a rack and pinion mechanism arranged todrive cushion assembly translation along the leg rest rails; and (iv) atiming link pivotably attached to the seat bottom arranged to actuatethe rack and pinion mechanism in response to angular movement of the legrest.
 2. The aircraft passenger seat of claim 1, wherein angulardeployment of the leg rest causes the timing link to actuate the rackand pinion mechanism to drive the cushion assembly away from the seatbottom to extend a length of the leg rest.
 3. The aircraft passengerseat of claim 1, wherein the rack and pinion mechanism comprises: anoutboard toothed rack fixed to the cushion assembly; an inboard toothedrack slidable along one of the leg rest rails and pivotably attached toone end of the timing link; and a pinion gear arranged between theoutboard and inboard toothed racks such that rotation of the pinion gearmoves the outboard and inboard toothed racks in opposite directions. 4.The aircraft passenger seat of claim 3, wherein the timing link ispivotably attached at one end to a horizontally oriented post positionedon one side of the inboard toothed rack.
 5. The aircraft passenger seatof claim 1, further comprising a locking gas spring arranged between theseat bottom and leg rest such that stowing the leg rest compresses thelocking gas spring and deploying the leg rest lengthens the locking gasspring.
 6. The aircraft passenger seat of claim 1, wherein a pivotattachment point of the leg rest rails to the seat bottom is spaced froma pivot attachment point of the timing link to the seat bottom.
 7. Theaircraft passenger seat of claim 1, wherein the cushion assemblyincludes a cushion carried on top of spaced frame members and front andrear transverse beam tubes.
 8. The aircraft passenger seat of claim 1,wherein the aircraft passenger seat is a fixed-shell seat including afixed shell positioned behind the seatback, and the leg rest deploysangularly toward horizontal.
 9. A fixed-shell aircraft passenger seatincluding an extendable and angularly deployable leg rest, comprising: aseat bottom; a seatback pivotably attached to the seat bottom; afixed-shell positioned behind the seatback; and a leg rest pivotablyattached to the seat bottom, comprising: (i) leg rest rails pivotablyattached to the seat bottom; (ii) a translating cushion assembly carriedon the leg rest rails; (iii) a translation mechanism arranged to drivecushion assembly translation along the leg rest rails; and (iv) a timinglink pivotably attached to the seat bottom arranged to actuate thetranslation mechanism in response to angular leg rest movement.
 10. Theaircraft passenger seat of claim 9, wherein angular deployment of theleg rest causes the timing link to actuate the translation mechanism todrive the cushion assembly away from the seat bottom to extend a lengthof the leg rest.
 11. The aircraft passenger seat of claim 9, wherein thetranslation mechanism is a rack and pinion mechanism, comprising: anoutboard toothed rack fixed to the cushion assembly; an inboard toothedrack slidable along one of the leg rest rails and pivotably attached toone end of the timing link; and a pinion gear arranged between theoutboard and inboard toothed racks such that rotation of the pinion gearmoves the outboard and inboard toothed racks in opposite directions. 12.The aircraft passenger seat of claim 11, wherein the timing link ispivotably attached at one end to a horizontally oriented post positionedon one side of the inboard toothed rack.
 13. The aircraft passenger seatof claim 9, further comprising a locking gas spring arranged between theseat bottom and leg rest such that stowing the leg rest compresses thelocking gas spring and deploying the leg rest lengthens the locking gasspring.
 14. The aircraft passenger seat of claim 9, wherein a pivotattachment point of the leg rest rails to the seat bottom is spaced froma pivot attachment point of the timing link to the seat bottom.
 15. Theaircraft passenger seat of claim 9, wherein the cushion assemblyincludes a cushion carried on top of spaced frame members and front andrear transverse beam tubes.
 16. The aircraft passenger seat of claim 9,wherein the leg rest deploys angularly to an angle short of horizontal.